The disclosure relates to high performance motorcycle components, and more particularly to a triple clamp for a motorcycle and other two-wheeled vehicles.
A motorcycle is equipped with a front end steering system including a front tire mounted to two front forks. The front forks are connected to handle bars. The front forks attach to the frame of the motorcycle with a triple clamp. The triple clamp comprises an upper triple clamp and a lower triple clamp. In each of the upper and lower triple clamps, a clamp or mount for each of the two front forks as well as a center steering pivot is provided. The center steering pivot is for mounting the front steering system to the frame via a pivot, typically a shaft. The handle bars couple to the upper triple clamp at handle bar mounting holes.
The front steering system functions through control commands to the handle bars that rotate the forks, triple clamps and wheel about the center pivot in a rotary manner. The capability for the front steering system to turn the motorcycle in a sharp turn as well as keep the motorcycle stable along a straight path at high speeds is of paramount importance.
Prior art motorcycle front steering systems have attempted to provide both the sharp turning capability and high-speed stability. The predominant means of providing the above features is to vary the relationship between the front forks and the center steering pivot. By altering the relationship between the front forks and the center steering pivot, the performance characteristics can be altered. Further detail must be provided in order to explain the alterations.
The relationship of the location of the front forks to the center steering pivot creates a variation in the steering response of the motorcycle. Referring to Prior Art FIG. 1, the upper triple clamp 10 is shown from a top view. The triple clamp 10 has a body 12 that includes a first fork clamp 14 and a second fork clamp 16 at opposite ends of the body 12. A center steering pivot 18 is defined in the body 12 between the first and second fork clamp 14, 16. A center steering pivot 18 centerline is shown as a dashed line 20 that bisects the center of the center steering pivot center 18. Another dashed line 22 represents the centerline of the fork clamps 14, 16. In FIG. 1, the line 22 is shown as offset 24 from line 20. The fork clamps 14, 16 are offset from the center steering pivot 18. Adjustment of the offset 24, results in performance changes in the steering system of the motorcycle.
The prior art devices have altered the offset 24 by manufacturing the triple clamp 10 with preset and fixed offsets 24. In order to adjust the steering system, for example to tune the steering for a race course with straight fast portions, the motorcycle would have to be placed in a shop or garage. The steering system would then be disassembled taking apart the steering system down to removal of the triple clamps from the frame. Replacement triple clamps would be installed and the entire steering system reassembled. This procedure is time consuming and is not easily done in the field, if at all.
Another relationship of the angle of the front forks and the center steering pivot creates a variation in the steering response of the motorcycle. Referring to Prior Art FIG. 2, a schematic of the motorcycle front wheel is illustrated. The motorcycle front wheel 30 contacts the surface of the ground at a ground contact patch 32. The extension of the center steering pivot along an imaginary line, called the steering pivot line 34, intersects the ground at a steering axis point 36. The dimension between the ground contact patch 32 and the steering axis point 36 is called the trail 38. The trail 38 influences the turning characteristics of two wheeled vehicles, such as motorcycles. The dimension between the steering pivot line 34 and the vertical centerline 40 of the wheel 30 is called the fork rake angle 42. As the rake angle 42 is varied, the trail 38 is varied. Another technique to vary the turning characteristics of the motorcycle is to vary the fork rake angle 42 thus varying the trail 38. Prior art techniques of altering the fork rake angle 42 are equally as cumbersome as the above described modifications to the offset.
What is needed in the art is an improved triple clamp that allows for easy adjustment of the steering system to customize and enhance the steering performance.